Multi-layered vegetation element

ABSTRACT

Multi-layered vegetation element for the greening of large rooftops, with the individual layers being mechanically interconnected by threads. A porous fibrous web is envisaged as the lowest layer, followed by a layer of stone wool and a layer incorporating seeds and living plant matter. A retention layer or protective layer serves as the uppermost layer. As an alternative embodiment, the porous fibrous web at the bottom is followed by a layer of mineral wool, which in turn is topped by a mixed cocos and plant layer being a cocos layer with an admixture of seeds and living plant matter.

The invention relates to a multi-layered vegetation element for thegreening of artificial level expanses such as rooftops or other areas,in particular for the greening of large areas such as the greening oflarge industrial rooftops.

Due to its positive aspects, the greening of artificial level expansesand in particular the greening of rooftops of buildings has long beenproven and popular. Generally speaking, in the case of large areas,greening by spray-on application is considered, with a green compoundbeing sprayed onto the rooftop in situ. Apart from this method it isalso well known to place rolls of ready-made precultivated vegetationmats on the roof where they are unrolled and laid. The present inventiondeals with this alternative to spray-on greening.

In practical operation the vegetation mats are precultivated on naturalsoil by the manufacturer. According to German patent DE 36 31 716 C2 andGerman patent DE 42 19 275 C2, with prior art the procedure is asfollows. A sealing foil is spread out on the natural soil and a supportstructure for the vegetation is placed on top of this foil. The foilseals the support structure so as to prevent root penetration into thenatural soil, of the plants to be cultivated.

Subsequently, substrate, seed, plant matter and fertiliser are placedonto or into the support structure, and then shade cloth is applied(protection against sun and wind).

Then follows an extensive period of horticultural care, watering andfertilising the plants until the support structure is completely greenand available for use as a ready-made vegetation mat for greening arooftop. It can take several months until the vegetation mats havecompletely greened and until the pre-cultivation period is completed.Only then can the vegetation mats be used for greening a roof.

Apart from the extensive pre-cultivation period it is alsodisadvantageous that the vegetation mats must be produced for inventorybuildup and kept in the manufacturer's care until such time as an orderfor the greening of a roof is obtained. Only then are the vegetationmats rolled up and transported to the desired destination. A furtherdisadvantage in this respect is that the rolls of precultivated,ready-made vegetation mats are very heavy, resulting in high freightcosts.

At their destination, the heavy rolls of vegetation mats must be takenonto the roof and placed in their final position. In these processestoo, the heavy weight of the rolls of vegetation mats is not compatiblewith ease of use.

If on the other hand, no customer is found for the readymade vegetationmats, there is the additional disadvantage of the entire pre-cultivatedmats having to be cared for over an ever increasing period and, in theworst case, even becoming unusable. Due to the extensive pre-cultivationperiod it is not always possible to produce the vegetation mats ondemand. Rather, the manufacturer has to bear the risk of pre-financingcultivation of vegetation mats.

It is an object of the invention to provide a vegetation element whichavoids the above-mentioned disadvantages to the manufacturer and makesit possible to produce the vegetation elements to firm requirements andboth to manufacture and lay them onto the desired area within a shorttime.

To achieve this object, the multi-layered vegetation element comprisesthe characteristics mentioned in the subsidiary claims 1 and 2.

An essential characteristic of the invention consists of the vegetationelement which comprises several mechanically interconnected layers,apart from seeds also containing an admixture of living plant matter.While seeds require a relatively long growth phase, the living plantmatter grows considerably faster. In addition, the application of livingplant matter means independence from seed production.

The use of living plant matter is to be seen in the context of theparticular layered construction of the vegetation element and also inthe context of the seeds. In the alternative embodiment according toclaim 1 the upper retaining layer, which serves as a protective layer,of the vegetation element takes on a particular role. Not only does thisretaining layer stop the plant matter or the seeds from being blown awayby the wind, but rather this retaining layer on top of the plant matterensures ground contact with the layer of mineral wool located below theliving plant matter. The upper retaining layer presses the plant matteragainst the mineral wool layer, thus improving root formation.

Of course, the use of living plant matter is only possible with certaintypes of plants, e.g. with succulents. Due to the simultaneous use ofseeds and plant matter, restriction to the same type of plant isrecommended. In this case, the seeds serve as a safety backup andreserve, in case not all plant matter grows completely. But it is alsoconceivable to use parts of one type of plant and seeds from another,different type of plant, together.

In the alternative embodiment according to the alternative independentclaim 2 the lowest layer of fibrous web is directly beneath a layer ofmineral wool and on top of this layer there is a mixed cocos and plantlayer made from a cocos layer with an admixture of seeds and livingplant matter. Thus this cocos layer already incorporates, asingredients, the seeds and the living plant matter which may also partlylay on top of the cocos layer.

In practice, the above-mentioned cocos and plant layer acts both as agrowth layer and as a retaining layer. The growing roots can penetratedown into the layer of mineral wool.

A decisive advantage of the invention consists of the pre-cultivationperiod as mentioned in the introduction not being applicable at all.Instead, it is possible to produce the vegetation elements according tothe invention based on actual demand and order position.

A further essential aspect of the invention arises from the vegetationelement not containing any substrate and thus in addition also beingcomparatively light. The substrate which is still essential for completegreening of the roof is first placed on the roof, with the vegetationelement according to the present invention being subsequently rolled outfor placement upon it.

Care must be taken that the vegetation elements according to the presentinvention have to be placed within the relatively short time of abouttwo days, otherwise there is the danger of the living plant matterspoiling. For, in the rolled-up state for transport to the site, warmthand humidity can easily develop in the vegetation elements and besides,there is hardly any light. Consequently, the living plant matter mayspoil to the point of becoming unusable if these factors exist for anextended period or if transportation takes too long.

Because pre-cultivation is no longer required, the costs of lengthy careare avoided and the disadvantage of possible overproduction forinventory buildup no longer applies. Rather, the possibility now existsof manufacturing the vegetation elements according to the presentinvention immediately upon receipt of an order, and of laying it withina short time on site on a roof where a substrate is in place.

Since there is no extended pre-cultivation period or since there is nosubstrate involved, the new vegetation elements are relatively light;only around 20% of the weight of ready-made greened and pre-cultivatedvegetation mats. Accordingly, freight costs are considerably reduced.

The low weight of the vegetation elements leads to still furtheradvantages. Handling, both at the place of manufacture and in particularat the destination, is much simpler and vegetation elements can be laidquickly. It is not even absolutely necessary that these tasks beaccomplished by an expert. This results in considerable financialbenefits.

To be sure, it may become necessary to water the vegetation elements inthe initial phase, but this factor is far outweighed by theabove-mentioned advantages.

The invention is particularly favourable when greening large areas, suchas large roofs of industrial buildings. Here, the advantages mentionedapply in particular, and above all the invention represents acost-effective alternative to spray-on greening which is in itself quitecompetitively priced.

Starting point of the invention was the object of avoiding expensive andtime-consuming pre-cultivation by producing, to firm requirements,vegetation elements which would be ready for use within a very shorttime on a roof where a substrate is in place. When compared to seeds,the living plant matter grows very quickly and once these new types ofvegetation elements are in position on the roof, the seed can germinatein situ while the living plant matter already assures a first flush ofgreenery. The invention is particularly favourable in the case of largerareas, from approx 5,000 m². With such expanses the advantagesmentioned, such as low freight costs, rapid placement and the absence ofany pre-cultivation period, are particularly noticeable.

Yet another particular advantage of the invention is the use of mineralwool, for example stone wool, because the mineral wool serves as awater-retaining layer. Water capacity is about 95%, i.e. the mineralwool can absorb and retain water at the rate of 95% of its weight. It isthus sufficient, after placement on the roof of the vegetation elementaccording to the invention or rather on the substrate in place on theroof, to provide one watering in order to bring about growth.

In addition, the mineral wool becomes heavy as a result of the waterabsorbed by it and thus makes a beneficial contribution to positionalsafety of the vegetation element on the roof, until the roots of thedeveloping plants have penetrated the substrate.

An appropriate embodiment of the invention also envisages the additionof fertiliser to the plant layer containing the living plant matter andseed. The substrate of the vegetation element which practically consistsof the lower layer of cocos and the mineral wool layer, can be regardedas being largely nutrient-neutral. In addition, the layer of mineralwool assumes a fire protection role. Preferably rock wool is used asmineral wool.

In the case of the invention, nutrient-neutral means that hardly anynutrients available to the plants are present, so that the addition ofslow-release nutrients may become necessary, preferably as organicnutrient combinations or so-called coated fertiliser. The plants canthus grow initially, but before long there would be insufficientnutrients to ensure further growth or further nutrient supply to theplants. It is therefore recommended to add such fertiliser.

According to another appropriate embodiment of the invention, the livingplant matter consists of sprouts of the genus Sedum which have proven tobe particularly suitable and which grow quickly.

In the two alternative embodiments of the invention according to thealternative independent claims 1 and 2, additionally, woven mesh is usedto advantage as the uppermost layer on top of the vegetation element.This woven mesh is to have sufficiently large mesh openings and is to bemechanically interconnected to all other layers of the vegetationelement, preferably by threads in the manner of a quilt. Thus thevegetation element as a whole forms a stable entity.

The woven mesh provides the advantage of enabling abutting or adjoiningwidths or lengths of the vegetation element to be fastened, i.e.interconnected. The adjoining or abutting mats or vegetation elementscan thus form one overall unit.

The woven mesh provides the additional advantage of counteracting thedanger of wind suction forces.

Further advantageous developments of the invention are listed in thedependent claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The objects and features of the invention will be better understood fromthe embodiments represented in the accompanying drawings in which:

FIG. 1 is a diagrammatic cross-sectional view of a vegetation elementaccording to a first alternative embodiment of the invention;

FIG. 2 is a diagrammatic cross-sectional view of a vegetation elementaccording to a second alternative embodiment of the invention; and

FIG. 3 is a view of a vegetation element according to FIG. 1 with anupper layer of gravel or pebble stones.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The vegetation element shown in FIG. 1 is a multi-layered vegetation mat10 that can be rolled up. A porous fibrous web 12 serves as the lowestlayer in a manner which is well known. On top of it there is a lowerlayer 14 made from cocos, with an approximate thickness in thisembodiment of about 1.0 cm.

On top of the lower layer 14 made from cocos there is a stone wool layer16, approximately 2.0 cm thick. On top of the stone wool layer 16 thereis a vegetation layer 18 comprising seeds and living plant matter. Thisis a growth layer for growing vegetation, in this embodiment comprisingthe plant genus Sedum. The seed too, is Sedum seed, and Sedum sproutsare used as living plant matter. In addition, the vegetation layer 18contains fertiliser (repository fertiliser for approximately 6 months).

The multy-layered construction of the rollable vegetation mat 10 isfinished off by an upper retaining layer 20 consisting of cocosmaterial. The retaining layer 20 serves as a protective layer andprevents removal of living plant matter and seeds by the wind. Inaddition, the retaining layer ensures ground contact of the living plantmatter to the stone wool layer 16, i.e. the living plant matter is tosome extent pressed against this stone wool layer 16 thus promoting rootgrowth.

The layers of the rollable vegetation mat are held together by threads22 in a manner of a quilt and thus mechanically interconnected so as toprovide the required stability and cohesion.

The thickness of the lower layer 14 made from cocos is about 1.0 cm,that of the mineral wool layer 16 approximately 2.0 cm and that of theretaining layer at the top 20 about 0.3 cm.

The following dimensions for the strips of rollable vegetation mats 10of FIG. 1 can be considered suitable: length 12.0 m; width 1.0 m; totalthickness approx. 3.3-3.5 cm--a unit delivered thus consists of 12 m².Weight at delivery is a mere 2.0 kg/m². Each unit delivered of 12 m²thus weighs 24.0 kg, very lightweight indeed.

When greening a roof it is envisaged that a sealing layer 32 be appliedto the roof 30, and a substrate layer 34 be placed on top of thissealing layer 32. Finally, the rollable vegetation mat 10 is laid orrolled out on top of this substrate layer 34.

In the case of the rollable vegetation mat 24 shown without a roof inFIG. 2, the mineral wool layer 16, here too preferably made from stonewool, is placed directly onto the lower layer of fibrous web 12. Thelower cocos layer 14, shown in FIG. 1, is thus not present.

On top of the mineral wool layer 16 there is a mixed cocos and plantlayer 26 made from a cocos layer mixed with seeds and living plantmatter. Seeds and living plant matter may partly also be located on topof this cocos and plant layer 26. As with the rollable vegetation mataccording to FIG. 1, fertiliser may also be added to the cocos and plantlayer 26.

Here the cocos and plant layer 26 acts both as a growth layer and aretaining layer (as described in the case of FIG. 1). In the embodimentshown, the thickness of the layer of cocos and plant matter is about 1.5cm; the weight per unit of area is 500 g/m².

When compared to the rollable vegetation mat 10 shown in FIG. 1, thevegetation mat 24 enables even more regular and intensive plant growth,because plant matter and seeds can develop better and more evenly insidethe cocos and plant layer 26.

Above the cocos and plant layer 26 there is a woven mesh 28 which mayalso be provided in the case of the alternative embodiment according toFIG. 1. The woven mesh 28 has been stitched together by threads 22 withthe other layers of the rollable vegetation mat 24, thus providingprotection from wind suction forces. This is advantageous in cases wherethe rollable vegetation mats 10 or 24 are used at a higher level, forexample on roofs, where there is a danger of the rollable vegetationmats or their layers being lifted off by wind suction forces and blownaway.

The rollable vegetation mat 10 or 24 can be produced very quickly ondemand, without a pre-cultivation period, and subsequently handledwithin only about 48 hours and rolled out on a roof 30 to be greened,where a substrate 34 is in position.

Once the rollable vegetation mat 10 or 24 according to the presentinvention has been laid onto the roof 30, it may take about 3-8 weeks ofcultivation time until the rollable vegetation mat 10 or 24 iscompletely greened.

By way of supplement it should be noted that the lower layer 14 madefrom cocos, as shown in FIG. 1 can assume a drainage function. Inaddition, the plant roots are able to reach into this lower layer 14made from cocos.

The cocos or cocos material used within the framework of this inventionmay comprise cocos fibres of various length or of cocos mulch or cocospeat, preferably bound, e.g. as a mat.

As a further embodiment of the invention, FIG. 3 depicts a rollablevegetation mat 10 according to FIG. 1, except that in addition a thinlayer of gravel or pebble stones 36 has been placed on top of thesurface of the rollable vegetation mat 10. This thin layer of gravel orpebble stones 36 serves to weigh down the rollable vegetation mat 10 (or24) and by increasing its overall weight enhances its positional safety.This counteracts the danger of the rollable vegetation mat 10 beinglifted off the rooftop as a result of wind suction forces.

In addition, the layer of gravel or pebble stones 36 is beneficial inassisting growth during dry weather, because humidity accumulating atnight can be stored underneath the individual pieces of gravel.

Besides, the individual stones which form the layer of gravel or pebblestones are only visible during the cultivation period. As the plantsgrow and the greenery takes over, the layer of gravel or pebble stonesis covered up by the plants.

As an alternative to the thin layer of gravel or pebble stones, the topof the rollable vegetation mat 10 or 24 may be fitted with wires or wiremesh coated in clay. In this way too, the rollable vegetation mat 10 or24 can be weighed down to ensure increased positional safety.

FIG. 1-3 shows the vegetation elements 10 before the greenery has takenover.

I claim:
 1. A rollable multi-layered vegetation element (10) for thegreening of artificial level expanses with the individual layers beingmechanically interconnected, comprising the following design of theindividual layers, from bottom to top:a porous fibrous web (12) as thelowest layer, a lower layer (14) made from cocos, a mineral wool layer(16) made from mineral wool, a vegetation layer comprising seeds andliving plant matter (18), an upper retaining layer (20) as a protectivelayer.
 2. Vegetation element according to claim 1, characterized in thatthe thickness of the vegetation layer is approx. 1.5 cm and the weightper unit or area is 500 g/square-meter.
 3. Vegetation element accordingto claim 1, characterized in that the vegetation layer (18) additionallycontains fertilizer.
 4. Vegetation element according to claim 1,characterized in that the upper retaining layer consists of cocosmaterial and is only approx. 0.3 cm thick and weighs only approx. 25g/square-meter.
 5. Vegetation element according to claim 1,characterized in that the living plant matter consists of succulentplants.
 6. Vegetation element according to claim 1, characterized inthat the living plant matter consists of Sedum sprouts.
 7. Vegetationelement according to claim 6, characterized in that the seeds and theliving plant matter is the same type of plant.
 8. Vegetation elementaccording to claim 1, characterized in that the total thickness of thevegetation element (10) is about 3.3 to 3.5 cm.
 9. Vegetation elementaccording to claim 1, characterized in that on top of the upperretaining layer a thin layer of gravel or pebble stones has been placed.10. Vegetation element according to claim 1, characterized in that onthe top of upper retaining layer wires or a wire mesh coated in clayhave been placed.
 11. A rollable multi-layered vegetation element (10)for the greening of artificial level expanses with the individual layersbeing mechanically interconnected, comprising the following design ofthe individual layers, from bottom to top:a porous fibrous web (12) asthe lowest layer, a mineral wool layer (16) made from mineral wool, amixed cocos and plant layer (26), made from a cocos layer mixed withseeds and living plant matter.
 12. Vegetation element according to claim11, characterized in that the thickness of the mixed layer of cocos andplant matter (26) is approx. 1.5 cm and the weight per unit of area is500 g/square-meter.
 13. Vegetation element according to claim 11,characterized in that as a further upper layer of a woven mesh (28) issuperimposed on top of the mixed cocos and plant layer, and the wovenmesh is mechanically interconnected with the layers below. 14.Vegetation element according to claim 13, characterized in that thewoven mesh (28) of abutting and adjoining vegetation elements aremechanically interconnected.
 15. Vegetation element according to claim11, characterized in that the mixed cocos and plant layer (26)additionally contains fertilizer.
 16. Vegetation element according toclaim 11, characterized in that the living plant matter consists ofsucculent plants.
 17. Vegetation element according to claim 11,characterized in that the living plant matter consists of Sedum sprouts.18. Vegetation element according to claim 17, characterized in that theseeds and the living plant matter is the same type of plant. 19.Vegetation element according to claim 10, characterized in that thetotal thickness of the vegetation element (10) is about 3.3 to 3.5 cm.